1. Technical Field
The present disclosure relates to systems and methods for detecting proximity of one or more objects relative to a user interface.
2. Background
A vehicle, such as an automobile, truck, boat, and the like typically includes one or more user interfaces accessible by occupants including an operator and/or passengers for displaying information and providing input for various accessories located in and/or around the vehicle. A user interface may include one or more controls that an occupant uses to control an accessory, in addition to a display for displaying status information for the vehicle and/or an accessory. In addition to accessories mounted in the vehicle, a user interface may be used to control portable accessories for the vehicle or occupants, such as personal electronic devices. As one example, a vehicle user interface may be used to control a wirelessly linked mobile phone when detected within proximity of the vehicle. As with the accessories, the user interface may be mounted in the vehicle, or may be portable. For example, a portable remote starter key fob with status display may be used to start the vehicle. Similarly, a hand-held user interface may be used to control an audio/video system or stereo system that may be permanently or removably mounted in the vehicle, for example.
User interfaces may be used in general-purpose passenger vehicles, as well as special-purpose commercial or industrial vehicles, to provide input to various types of devices or accessories associated with the vehicle operation or purpose. For example, delivery vehicles may include hand-held bar code readers to identify and track packages. Such tools may be independent of the vehicle, or may interface with one or more vehicle systems, such as a vehicle cellular or satellite communications system to send or receive delivery information, for example. The bar code reader functions as a user interface or input device to provide information to the operator or to a remote location, such as a central dispatch computer, for example. Information may include the status of a particular package, the source, destination, etc. and is typically manually updated by the driver when scanning a bar code or similar packaging identifying information.
In various types of vehicles, one user interface, referred to as the instrument cluster, is located behind the steering wheel for access by the operator of the vehicle. Another user interface, referred to as the center stack console, is accessible to the operator and any front seat passengers. Other areas of a vehicle that may have user interfaces for control and/or information display include door armrests, where window, mirror, and security controls may be placed, and overhead consoles where sunroof and interior lighting controls may be placed, for example. Of course, the particular type of user interface and its location may vary depending on the type of information displayed or accessory being controlled across a wide variety of applications.
Various user interfaces, such as the center stack console, for example, may include controls and a display associated with multiple accessories, such as audio, navigation, and climate control (heating, ventilating, and air conditioning) accessories, for example. The surface of the user interface is divided into adjacent areas each being associated with an accessory. Each area of the user interface has controls positioned adjacent to a portion of the display. Many of the controls are typically implemented as mechanical switches such as pushbutton switches, rockers, slide switches, and rotary switches that an operator uses to control various functions of the corresponding accessories. These switches operate using mechanical mechanisms to complete electrical contact. As a result, mechanical switches may exhibit reduced performance over time as activation causes wear on moving components and electrical contacts. Switch reliability declines and contacts may become intermittent with continued use. In addition, repeated physical contact may lead to deterioration of switch face legends and graphics. Mechanical switches are also susceptible to contamination from external matter like dirt, food, and liquids. Ultimately, mechanical switches are expensive for automotive use. In today's automobile, mechanical switches as the controls for vehicle accessories are responsible for some $400 or so of the automobile cost.
In addition to inherent physical limitations and cost, mechanical switches present constraints to automotive ergonomics and aesthetics by limiting vehicle styling and layout options. In particular, mechanical switches are permanently fixed, numerous, and occupy relatively large portions of the surface of the user interface. For example, a standard HVAC system requires controls for adjusting vent selection, blower motor speed, temperature, etc. The controls may be doubled to accommodate individual comfort control between the driver and a passenger. In a luxury class vehicle, the HVAC system may further require controls for heated mirrors, heated seats, rear passenger air flow, etc.
As vehicle accessories are augmented with additional features, the user interface used to control these accessories becomes increasingly complex. Additional accessory features are accompanied by more controls and adding mechanical switches may increase the size of the interface. If the interface has a display associated with the accessory, expansion of the control interface may be necessary to accommodate operator control of the additional features. Together, the mechanical switches and the displays of a control interface consume valuable space of the surface of the control interface and increase overall cost.
Mechanical switches should be arranged to provide comprehensive and intuitive accessory control for the user. Excessive buttons or knobs clutter the interface and may result in the operator hunting for a desired switch. Sophisticated multi-function control knobs, those with switches that activate by tilting, pivoting, or swiveling, may have obscure functions and may be difficult to maneuver for some operators. Furthermore, sophisticated control knobs have many intricate parts making them expensive and prone to failure.